Haselhoff, E., R. J. Boerman, and J.-W. Bobbink. “An Experimental Study for Reproduction of Biological Anomalies Reported in the Hoeven 1999 Crop Circle”. Journal of Scientific Exploration, vol. 28, no. 1, May 2014, https://journalofscientificexploration.org/index.php/jse/article/view/701.